Mums partner 6 yrs want's her to lend him all her life saving for a loan to buy larger house she won't be on deed for.

This has all the calling cards of a scam though, doesn't it?

1. Sense of urgency
2. "Trust me"
3. "Can't do this any other way"
4. "You'll get the money back straight away"

End result is your Mum has a DP with two houses bought and paid for in his name, not married, not in the Will and she has her life savings drained.

If this was £20k I'd say it's a fairly cheap way to find out who a person really is.

But £250k? Jesus fucking christ I don't think I'd even give my own mother that amount.

Absolutely not.
if one of my children did this, I would be frogmarching them to a solicitors to discuss all of the implications behind it.
And persuading them not to do it.
It could be the best £350 plus VAT you’ve ever spent

Goodness, no. There will be other houses.

She would be daft to do this.
Hes protecting his childrens inheritance very carefully isnt he, but noones worried about yours!
I think your mum needs to tell him that unless they get married or she is put on the deeds, then it would be a financially stupid move.

My heart is racing reading this, it's giving really bad vibes to me.

We all agree she mustn't do this. I'll see all your red flags and concerns and raise them to this man has sinister, criminal thinking.
Genuinely think she needs to get rid of him now and stop all contact. Ensure her finances are safe but also her general health. She must already be feeling confused by all this, that's a slippery slope. I may be being a tad dramatic but it sounds like a script from a true crime doc.
Do some digging on him OP.

If she consult a solicitor (as suggested already), she should see if the loan can be registered as a charge against the property to protect her investment.

Absolutely not. He doesn't get to protect his assets while dipping into hers, even if it is temporary.

Are they moving in together? But he won’t put her on the deeds? What happens if the split up or he dies? She’ll be homeless and her savings will be gone.

An unsecured £250 000 loan? Hahahahahaha.

Someone's having a laugh.

She needs to put a charge on the property so he can't sell or transfer it without paying back what he owes her

https://www.gov.uk/government/publications/form-n379-application-for-charging-order-on-land-cpr-part-73

https://www.weightmans.com/insights/establishing-beneficial-interest-in-property/

https://vaneatonsolicitors.co.uk/claim-joint-ownership/

https://england.shelter.org.uk/professional_resources/legal/relationship_breakdown/housing_rights_of_cohabiting_sole_homeowners/occupation_rights_if_one_partner_is_the_sole_owner

A bridging loan makes sense, though is expensive. Or could she could say that if her money is used, they buy as tenants in common with her then owning a percentage? Re. inheritance, her share would go to her family, his share to his. If they split, she'd only get her money once the house is sold, but it would probably have appreciated in value more than in a bank and it sounds like she doesn't expect to split.

I agree, if this man uses the 'if you loved me you'd do it' tactic then she needs to fire back with 'if you love me you wouldn't put me in this position'.
Your mum should say no op, any pushback from him and she should double down on that no.
But she loves him (in other words she's under his spell) will she be strong enough to stand up to him?

No way. If she's not married or on the deeds then NO!
Please show her this thread.

If she wants to go to counselling in the first place, and there's no indication that she is looking to do so. The counsellor wouldn't be offering advice though.

And no decent person would ask it of her

That's the crux of the matter isn't it. He is not a 'nice guy'.
Doing this would be insanity.

More red flags than a Communist parade 🚩🚩🚩🚩🚩

She's worried but she also trusts him.

She should not trust him.

I used to work in debt advisory/recovery.

Please tell your mum not to do this.
Even if he's 100% honest and well intended, people die, get ill, get fired, have mental breakdowns, other family complications etc. Things often don't work out intended.

If she won't like to you, take her to a solicitor so she's at least away of what she's doing, fully understands it and is protected as possible.

If a mainstream bank (who exists to make money in loans!) won't give someone money, then they don't expect to get it back. If they did, they would lend, their profits need them to issue good loans. If experts team him a bad risk, then he is a bad risk.

She has a much higher risk of losing the money than getting it back.

If the mother is concerned about undue financial pressures (or other pressures) in her relationship a counsellor can help her to assess them.

Agree, I wonder if he he knew about her money somehow and then targeted her? Refusing to get married and purchase the house jointly, yet borrowing a huge sum of money in an unsecured loan, indicates someone with suspicious intentions. Please make your mother get proper legal advice if she continues to consider this.

If something were to go wrong she's left totally high end dry with no savings and no home.

Hell, no! She cannot place herself in this position.

And no decent person would ask it of her.

A counsellor wouldn't get involved in something like this.

"If" being the vital word, though. No one can take a chance on an "If".
If is neither use not orniment when she's lost all her money and doesn't have a leg to stand on. How long has he known about your Mum's life savings. I'm not saying he has (well how would I know) who's to say he hasn't been planning for your years to get a loan and do runner.
You can't deny that it's suspicious that he won't put her name on the deeds.
If she was to do it she needs God Almighty himself to give her guarantees and absolutes.